If there isn't such a thing as geek lit, there should be: it would be appropriate to the exaggerated infantilism that energises much contemporary literature and film in the west, the gremlins and green men that quicken the hearts of children, adults and publicists and whose creators VS Naipaul found himself scolding. For the computer geek, after all, is a sort of overgrown child, maladjusted among his or her own kind, and, secretly, something of a wizard. You don't need a JK Rowling to imagine him (and it's usually a him) into existence: the geek has been around for some 20 years now.

Is Transmission, Hari Kunzru's second novel, geek lit? Or is it a subtle, often humorous, analysis of the infantilism that, everywhere, defines the culture we live in? Certainly, its protagonist is a geek. Arjun Mehta, who grew up in the suburbs of New Delhi, is a talented if slightly dysfunctional young man who seems to his parents and sister to be going nowhere, until he appears for an interview with a suave Indian representative of a Californian computer firm, and finds himself with a passport and a visa to America.

Once he's in Silicon Valley, though, he finds he doesn't quite have the job he imagined. He is, rather, what one Indian academic with bluff grandiloquence termed a "cyber-coolie" (though the academic was referring to employees at Indian call-centres): a minor, expendable software programmer who has to scavenge for jobs. Then there is a change of fortune: he gets a job in Virugenix - "not just any job, but a position in the holy of holies, home of the Ghostbusters, the Cyrus J Greene Labs". Arjun is still half-child; still, in his 20s, a virgin. His sexual innocence comes to an end when a colleague, Christine, charitably decides to have sex with him: a drunken, semiconscious act which is, in a way, a rewriting of the strange sex scene that opened Kunzru's first novel, The Impressionist .

Then Arjun's luck changes again: the IT bubble bursts and he is threatened with redundancy. To save his job (for his own sake, and his family's), he, like the German teenager who recently gave the world the Sasser worm, releases a virus with the name of a Bollywood actress, Leela Zahir, into cyberspace. His intentions aren't wholly dishonourable - he'd meant to revive not only his own fortunes, but Virugenix's, and he didn't suspect the damage the virus was capable of doing. This, then, like the Sasser worm, is the dark side of infantilism and magic.

As markets and firms crash while the virus multiplies, the other lives that Kunzru had so far carefully built around Mehta's - those of Guy Swift, creator of brands and images; his beautiful wife, Gabriella, film publicist among other things; Leela Zahir, shooting on location in Scotland - fall apart. The lives of the four main characters are utterly changed by the end; they either die, or are transformed, or they disappear. This attrition of identity is reminiscent of the fate that the Eurasian protagonist of Kunzru's first novel meets somewhere in America, where, captured by a tribe, he gradually loses consciousness of himself. There is, of course, a literary tradition for such extreme narratives of escape, loss and transformation; one thinks of the Mexico of DH Lawrence's fiction, and the north Africa of Paul Bowles's, in which characters under duress in alien environments lose their sense of who they are.

But those narratives were driven by the disgust their authors felt towards the societies they lived in, and the veneer of civilisation you needed to inhabit those societies, a disgust far more savage than the satire and comedy in Kunzru's novel will allow for. Kunzru is partly disillusioned and partly beglamoured by the world of technology and magic he writes about. And so he's written, expertly, a successful and intelligent piece of entertainment, a more compelling read, if anything, than his first novel, a book that, to a certain extent, subscribes to and is impelled by the romance of the cyberworld by which its characters are undone.

Amit Chaudhuri's Real Time is published by Picador. Hari Kunzru appears at the Guardian Hay festival today.